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Retrieval-Based Word Learning in Developmental Language Disorder: Verb Learning

Retrieval-Based Word Learning in Developmental Language Disorder: Verb Learning

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06001866
Enrollment
31
Registered
2023-08-21
Start date
2023-03-01
Completion date
2024-01-25
Last updated
2025-08-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Developmental Language Disorder, Language Development, Specific Language Impairment

Keywords

word learning, word retrieval, preschool-aged children

Brief summary

Children with developmental language disorder (DLD; also referred to as specific language impairment) experience a significant deficit in language ability that is longstanding and harmful to the children's academic, social, and eventual economic wellbeing. Word learning is one of the principal weaknesses in these children. This project focuses on the word learning abilities of four- and five-year-old children with DLD. The goal of the project is to build on the investigators' previous work to determine whether, as has been found thus far, special benefits accrue when these children must frequently recall newly introduced words during the course of learning. The focus of the current study is verb-learning. The goal of the study is to increase children's absolute levels of verb learning while maintaining the advantage that repeated retrieval holds over comparison methods of learning.

Detailed description

Developmental Language Disorder (DLD) affects language learning in an estimated 7% of children. Although much of the research literature has emphasized difficulties learning grammar, children with DLD also have major deficits in vocabulary. In recent work, the investigators have been examining the benefit of retrieval practice to enhance word learning and retention in preschoolers with DLD. The rationale behind this work is grounded in the growing literature in the field of cognitive psychology which shows that repeated practice in retrieving information results in greater long-term retention than continuous study of that information without opportunities for retrieval. In addition, retrieval practice that occurs after a delay-or spacing between study of a word and subsequent recall attempts-can lead to stronger effects. The investigators have explored the benefits of retrieval practice for preschoolers with DLD and with typical language development (TD), showing that recall and retention for novel words (nouns, adjectives, verbs) were greater when learned using repeated spaced retrieval (RSR) than when learned using repeated study only. Despite benefitting from RSR, children with DLD still showed lower levels of recall than children with TD, in particular in novel verb learning. In the current study, the investigators seek to improve the absolute levels of word form recall for verbs by modifying the method used previously. Sixteen children with DLD will be recruited for this study along with 16 children with TD matched on chronological age. Using a within-subjects design, children will learn eight novel verbs, four at a time. Each set of four will be learned over two consecutive days, with two words in the RSR condition and two words in a repeated study condition. The referents for these novel words will be video-recorded transitive actions performed by actors on objects and presented on a laptop screen. In the RSR condition, children will initially hear the word paired with a video of a novel action, immediately be asked to recall the word, and then see/hear it again. After three other words are presented, they will be asked to recall the original word again; this 3 spaced retrieval schedule will continue for the rest of the learning session. In the comparison condition, children will simply hear the words paired with a video of the novel action. In this study, during retrieval practice, children will be prompted to respond with a full sentence containing the verb. Recall of the verbs will be tested after the learning session on the second day and one week later. At one week, children will also complete a syntactic generalization test in which they are prompted to use the novel verb in a type of sentence that is different from the one used during learning. Finally, children will complete a two-alternative recognition test. The investigators hypothesize that novel verbs that undergo RSR during the learning period will be learned and recalled better than comparable novel verbs that are assigned to the repeated study condition. This RSR advantage will continue to be observed when the children must use the novel verbs with new actors and objects and will be seen as well in the syntactic generalization test when the children must use the novel verbs in a new sentence frame. Introducing novel verbs representing actions that can be performed on varying objects is expected to improve overall learning. In addition, by having the child produce the verbs in the context of a full sentence, the newly learned verbs should become more integrated with other sentence elements (subjects and direct objects), resulting in a richer representation in memory and consequently, greater recall, recognition, and syntactic flexibility than was observed in the previous novel verb study.

Interventions

BEHAVIORALRetrieval-based verb learning: Repeated Spaced Retrieval condition

A set of novel verbs are practiced on 2 consecutive days (the same verbs are used each day). Half of the novel verbs are learned in the repeated spaced retrieval condition and half are learned in the repeated study condition, with the two conditions interleaved on each day. The repeated spaced retrieval condition consists of study and retrieval trials. At the start of the sessions, retrieval trials immediately follow study trials. Thereafter, retrieval trials are spaced for each verb, occurring after 3 other words have intervened between the retrieval trial and the last study trial for that verb.

BEHAVIORALRetrieval-based verb learning: Repeated Study condition

A set of novel verbs are practiced on 2 consecutive days (the same verbs are used each day). Half of the novel verbs are learned in the repeated spaced retrieval condition and half are learned in the repeated study condition, with the two conditions interleaved on each day. The repeated study condition consists of study trials only (with no retrieval practice).

Sponsors

National Institute on Deafness and Other Communication Disorders (NIDCD)
CollaboratorNIH
Purdue University
Lead SponsorOTHER

Study design

Allocation
NON_RANDOMIZED
Intervention model
FACTORIAL
Primary purpose
BASIC_SCIENCE
Masking
NONE

Intervention model description

Within-participant design in which each child learns words under two conditions.

Eligibility

Sex/Gender
ALL
Age
48 Months to 71 Months
Healthy volunteers
Yes

Inclusion criteria

* a significant deficit in language ability (language test score below cutoff for best sensitivity/specificity) or documented age-appropriate language ability. normal hearing no evidence of neurological damage or disease scores on tests of nonverbal intelligence above the intellectual disability range not within Autistic range on Autism screening test native English speaker (can be bilingual)

Exclusion criteria

* failed hearing screening known neurological damage or disease scores on tests of nonverbal intelligence below the intellectual disability range (standard score less than 75) autism spectrum disorder non-native English speaker

Design outcomes

Primary

MeasureTime frameDescription
Verb Recognition (Number of Words Accurately Identified) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions for Generalized Items.1 week after Day 2 (second day) learning period.One week after the learning session, child is asked to indicate (by pointing) which of 2 video options is referred to upon hearing a sentence using a novel word learned in either the repeated spaced retrieval or repeated study condition. Each verb is tested with two items which used videos of agent-object pairs that were new (that the child had not seen during the learning period), for a total of eight items.
Accuracy of Verb Recall (Number of Verbs Correctly Recalled) in a New Structure in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions1 week after Day 2 (second day) learning period.Child is asked to describe the video of a novel action using the novel verb in a frame different from the one learned (i.e.,X likes to VERB the Y) in repeated spaced retrieval and repeated study conditions. Each verb is tested with four items: three items made use of videos of agent-object pairs the child had seen during the learning period and one item used an agent-object pair that was new. There were eight items total per condition.
Verb Recognition (Number of Words Accurately Identified) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions for Learned Items.1 week after Day 2 (second day) learning period.One week after the learning session, child is asked to indicate (by pointing) which of 2 video options is referred to upon hearing a sentence using a novel word learned in either the repeated spaced retrieval or repeated study condition. Each verb is tested with two items which used videos of agent-object pairs that the child had seen during the learning period, for a total of eight items.
Verb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 5 Mins. for Learned Items5 minutes after end of Day 2 (second day) learning period.Five minutes after second learning session, child is asked to recall and say the word associated with each novel action learned under each of the two conditions: a condition in which spaced retrieval trials occurred and one in which there were no retrieval trials. For Learned items, each of the four verbs was tested with videos of two of the agent-object pairs the child had seen during the learning period, for a total of 8 recall items. Children were prompted to retrieve/produce the novel verbs in the sentence structure used during learning.
Verb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 5 Mins. for Generalized Items5 minutes after end of Day 2 (second day) learning period.Five minutes after second learning session, child is asked to recall and say the word associated with each novel action learned under one of two conditions: a condition in which spaced retrieval trials occurred and one in which there were no retrieval trials. For Generalized items each of the four verbs was tested with videos of two agent-object pairs that were new (that the child had not seen during the learning period), for a total of 8 recall items. Children were prompted to retrieve/produce the novel verbs in the sentence structure used during learning.
Verb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 1 Week for Learned Items.1 week after Day 2 (second day) learning period.One week after second learning session, child is asked to recall and say the word associated with each novel action learned under one of two conditions: a condition in which spaced retrieval trials occurred and one in which there were no retrieval trials. For Learned items, each of the four verbs was tested with videos of two of the agent-object pairs the child had seen during the learning period, for a total of 8 recall items. Children were prompted to retrieve/produce the novel verbs in the sentence structure used during learning.
Verb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 1 Week for Generalized Items1 week after Day 2 (second day) learning period.One week after second learning session, child is asked to recall and say the word associated with each novel action learned under one of two conditions: a condition in which spaced retrieval trials occurred and one in which there were no retrieval trials. For Generalized items, each of the four verbs was tested with videos of two agent-object pairs that were new (that the child had not seen during the learning period), for a total of 8 recall items. Children were prompted to retrieve/produce the novel verbs in the sentence structure used during learning.

Secondary

MeasureTime frameDescription
Maternal Education in Yearsinformation collected at start of studyEducational attainment of child's mother in terms of years of education
Peabody Picture Vocabulary Test, Fifth EditionTest completed at start of studyThe Peabody Picture Vocabulary is an individually administered, norm-reference test that assesses receptive vocabulary (ability to understand individual words) for children and adults ages 2 years 6 months to 90 years and older. Standard scores are derived from number correct. Standard scores can range from a minimum of 40 and 160. Standard scores between 85 and 115 (1 standard deviation above and below the mean of 100) are interpreted as reflecting receptive vocabulary levels expected for age. Scores below 85 are interpreted as reflecting receptive vocabulary levels below what is expected for age.Scores above 115 are interpreted as reflecting receptive vocabulary levels above what is expected for age.

Countries

United States

Participant flow

Recruitment details

Children with DLD are recruited primarily through speech pathologists and preschool teachers. They are provided with eligibility guidelines and a parent letter. Once the parent is given the letter, they choose to contact us, if interested. Children with typical language development are recruited through advertising in preschools.

Pre-assignment details

Children are initially tested to see if they meet the inclusionary and exclusionary criteria of Developmental Language Disorder. These include falling below age level on a language test, while passing a hearing screening, a non-verbal IQ test, and an autism screener. Many children who are recruited and consented do not meet all these criteria pointing to the fact that DLD is not readily recognizable to non-professionals (parents, preschool teachers).

Participants by arm

ArmCount
Children With Developmental Language Disorder
These children have a significant delay in language development in the absence of hearing impairment, cognitive delay, autism, or neurological injury/disease.
14
Children With Typical Language Development
Children whose language development is as expected for their age.
13
Total27

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyProtocol Violation02
Overall StudyWithdrawal by Subject02

Baseline characteristics

CharacteristicChildren With Developmental Language DisorderChildren With Typical Language DevelopmentTotal
Age, Continuous57.21 months
STANDARD_DEVIATION 5.19
59.00 months
STANDARD_DEVIATION 5.26
58.07 months
STANDARD_DEVIATION 5.2
Ethnicity (NIH/OMB)
Hispanic or Latino
1 Participants0 Participants1 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
13 Participants13 Participants26 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Maternal Education in Years16.71 years
STANDARD_DEVIATION 3.36
17.42 years
STANDARD_DEVIATION 2.63
17.06 years
STANDARD_DEVIATION 2.89
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Asian
1 Participants0 Participants1 Participants
Race (NIH/OMB)
Black or African American
2 Participants1 Participants3 Participants
Race (NIH/OMB)
More than one race
1 Participants1 Participants2 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants0 Participants0 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants0 Participants0 Participants
Race (NIH/OMB)
White
10 Participants11 Participants21 Participants
Region of Enrollment
United States
14 participants13 participants27 participants
Sex: Female, Male
Female
9 Participants7 Participants16 Participants
Sex: Female, Male
Male
5 Participants6 Participants11 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 140 / 13
other
Total, other adverse events
0 / 140 / 13
serious
Total, serious adverse events
0 / 140 / 13

Outcome results

Primary

Accuracy of Verb Recall (Number of Verbs Correctly Recalled) in a New Structure in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions

Child is asked to describe the video of a novel action using the novel verb in a frame different from the one learned (i.e.,X likes to VERB the Y) in repeated spaced retrieval and repeated study conditions. Each verb is tested with four items: three items made use of videos of agent-object pairs the child had seen during the learning period and one item used an agent-object pair that was new. There were eight items total per condition.

Time frame: 1 week after Day 2 (second day) learning period.

ArmMeasureGroupValue (MEAN)Dispersion
Children With Developmental Language DisorderAccuracy of Verb Recall (Number of Verbs Correctly Recalled) in a New Structure in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) ConditionsRepeated Spaced Retrieval5.29 number of verbs recalledStandard Error 1.22
Children With Developmental Language DisorderAccuracy of Verb Recall (Number of Verbs Correctly Recalled) in a New Structure in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) ConditionsRepeated Study5.57 number of verbs recalledStandard Error 1.41
Children With Typical Language DevelopmentAccuracy of Verb Recall (Number of Verbs Correctly Recalled) in a New Structure in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) ConditionsRepeated Spaced Retrieval10.23 number of verbs recalledStandard Error 1.27
Children With Typical Language DevelopmentAccuracy of Verb Recall (Number of Verbs Correctly Recalled) in a New Structure in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) ConditionsRepeated Study7.38 number of verbs recalledStandard Error 1.47
p-value: =0.75LSD test
p-value: <0.01LSD test
Primary

Verb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 1 Week for Generalized Items

One week after second learning session, child is asked to recall and say the word associated with each novel action learned under one of two conditions: a condition in which spaced retrieval trials occurred and one in which there were no retrieval trials. For Generalized items, each of the four verbs was tested with videos of two agent-object pairs that were new (that the child had not seen during the learning period), for a total of 8 recall items. Children were prompted to retrieve/produce the novel verbs in the sentence structure used during learning.

Time frame: 1 week after Day 2 (second day) learning period.

ArmMeasureGroupValue (MEAN)Dispersion
Children With Developmental Language DisorderVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 1 Week for Generalized ItemsGeneralized 1 week RSR condition3.57 number of verbs recalledStandard Error 0.61
Children With Developmental Language DisorderVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 1 Week for Generalized ItemsGeneralized 1 week RS condition3.57 number of verbs recalledStandard Error 0.56
Children With Typical Language DevelopmentVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 1 Week for Generalized ItemsGeneralized 1 week RSR condition5.38 number of verbs recalledStandard Error 0.63
Children With Typical Language DevelopmentVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 1 Week for Generalized ItemsGeneralized 1 week RS condition3.92 number of verbs recalledStandard Error 0.58
p-value: =1LSD test
p-value: <0.00001LSD test
Primary

Verb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 1 Week for Learned Items.

One week after second learning session, child is asked to recall and say the word associated with each novel action learned under one of two conditions: a condition in which spaced retrieval trials occurred and one in which there were no retrieval trials. For Learned items, each of the four verbs was tested with videos of two of the agent-object pairs the child had seen during the learning period, for a total of 8 recall items. Children were prompted to retrieve/produce the novel verbs in the sentence structure used during learning.

Time frame: 1 week after Day 2 (second day) learning period.

ArmMeasureGroupValue (MEAN)Dispersion
Children With Developmental Language DisorderVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 1 Week for Learned Items.Learned 1 week RSR condition3.64 number of verbs recalledStandard Error 0.62
Children With Developmental Language DisorderVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 1 Week for Learned Items.RS condition3.50 number of verbs recalledStandard Error 0.62
Children With Typical Language DevelopmentVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 1 Week for Learned Items.Learned 1 week RSR condition5.46 number of verbs recalledStandard Error 0.64
Children With Typical Language DevelopmentVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 1 Week for Learned Items.RS condition3.77 number of verbs recalledStandard Error 0.65
p-value: =0.78LSD test
p-value: <0.00001LSD test
Primary

Verb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 5 Mins. for Generalized Items

Five minutes after second learning session, child is asked to recall and say the word associated with each novel action learned under one of two conditions: a condition in which spaced retrieval trials occurred and one in which there were no retrieval trials. For Generalized items each of the four verbs was tested with videos of two agent-object pairs that were new (that the child had not seen during the learning period), for a total of 8 recall items. Children were prompted to retrieve/produce the novel verbs in the sentence structure used during learning.

Time frame: 5 minutes after end of Day 2 (second day) learning period.

ArmMeasureGroupValue (MEAN)Dispersion
Children With Developmental Language DisorderVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 5 Mins. for Generalized ItemsGeneralized 5 min RSR condition3.79 number of verbs recalledStandard Error 0.58
Children With Developmental Language DisorderVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 5 Mins. for Generalized ItemsGeneralized 5 min RS condition2.43 number of verbs recalledStandard Error 0.57
Children With Typical Language DevelopmentVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 5 Mins. for Generalized ItemsGeneralized 5 min RSR condition4.85 number of verbs recalledStandard Error 0.6
Children With Typical Language DevelopmentVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 5 Mins. for Generalized ItemsGeneralized 5 min RS condition3.46 number of verbs recalledStandard Error 0.59
p-value: <0.00001LSD test
p-value: <0.00001LSD test
Primary

Verb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 5 Mins. for Learned Items

Five minutes after second learning session, child is asked to recall and say the word associated with each novel action learned under each of the two conditions: a condition in which spaced retrieval trials occurred and one in which there were no retrieval trials. For Learned items, each of the four verbs was tested with videos of two of the agent-object pairs the child had seen during the learning period, for a total of 8 recall items. Children were prompted to retrieve/produce the novel verbs in the sentence structure used during learning.

Time frame: 5 minutes after end of Day 2 (second day) learning period.

ArmMeasureGroupValue (MEAN)Dispersion
Children With Developmental Language DisorderVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 5 Mins. for Learned ItemsLearned 5 min RSR condition3.79 number of verbs recalledStandard Error 0.6
Children With Developmental Language DisorderVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 5 Mins. for Learned ItemsLearned 5 min RS condition2.86 number of verbs recalledStandard Error 0.63
Children With Typical Language DevelopmentVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 5 Mins. for Learned ItemsLearned 5 min RSR condition5.31 number of verbs recalledStandard Error 0.63
Children With Typical Language DevelopmentVerb Recall Accuracy (Number of Verbs Correctly Recalled) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions at 5 Mins. for Learned ItemsLearned 5 min RS condition3.38 number of verbs recalledStandard Error 0.65
p-value: <0.0001LSD test
p-value: <0.00001LSD test
Primary

Verb Recognition (Number of Words Accurately Identified) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions for Generalized Items.

One week after the learning session, child is asked to indicate (by pointing) which of 2 video options is referred to upon hearing a sentence using a novel word learned in either the repeated spaced retrieval or repeated study condition. Each verb is tested with two items which used videos of agent-object pairs that were new (that the child had not seen during the learning period), for a total of eight items.

Time frame: 1 week after Day 2 (second day) learning period.

ArmMeasureGroupValue (MEAN)Dispersion
Children With Developmental Language DisorderVerb Recognition (Number of Words Accurately Identified) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions for Generalized Items.Generalized RSR condition7.36 verbs wtih correct video identifiedStandard Error 0.23
Children With Developmental Language DisorderVerb Recognition (Number of Words Accurately Identified) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions for Generalized Items.Generalized RS condition7.14 verbs wtih correct video identifiedStandard Error 0.23
Children With Typical Language DevelopmentVerb Recognition (Number of Words Accurately Identified) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions for Generalized Items.Generalized RSR condition7.61 verbs wtih correct video identifiedStandard Error 0.24
Children With Typical Language DevelopmentVerb Recognition (Number of Words Accurately Identified) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions for Generalized Items.Generalized RS condition7.77 verbs wtih correct video identifiedStandard Error 0.24
p-value: =0.16LSD test
p-value: =0.33LSD test
Primary

Verb Recognition (Number of Words Accurately Identified) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions for Learned Items.

One week after the learning session, child is asked to indicate (by pointing) which of 2 video options is referred to upon hearing a sentence using a novel word learned in either the repeated spaced retrieval or repeated study condition. Each verb is tested with two items which used videos of agent-object pairs that the child had seen during the learning period, for a total of eight items.

Time frame: 1 week after Day 2 (second day) learning period.

ArmMeasureGroupValue (MEAN)Dispersion
Children With Developmental Language DisorderVerb Recognition (Number of Words Accurately Identified) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions for Learned Items.Learned RSR Condition7.00 verbs with correct video identifiedStandard Error 0.24
Children With Developmental Language DisorderVerb Recognition (Number of Words Accurately Identified) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions for Learned Items.Learned RS condition7.00 verbs with correct video identifiedStandard Error 0.24
Children With Typical Language DevelopmentVerb Recognition (Number of Words Accurately Identified) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions for Learned Items.Learned RSR Condition7.92 verbs with correct video identifiedStandard Error 0.25
Children With Typical Language DevelopmentVerb Recognition (Number of Words Accurately Identified) in Repeated Spaced Retrieval (RSR) and Repeated Study (RS) Conditions for Learned Items.Learned RS condition8.00 verbs with correct video identifiedStandard Error 0.25
p-value: <0.00001LSD test
p-value: =0.62LSD test
Secondary

Maternal Education in Years

Educational attainment of child's mother in terms of years of education

Time frame: information collected at start of study

ArmMeasureValue (MEAN)Dispersion
Children With Developmental Language DisorderMaternal Education in Years16.71 yearsStandard Deviation 3.36
Children With Typical Language DevelopmentMaternal Education in Years17.42 yearsStandard Deviation 2.36
p-value: <0.001t-test, 2 sided
Secondary

Peabody Picture Vocabulary Test, Fifth Edition

The Peabody Picture Vocabulary is an individually administered, norm-reference test that assesses receptive vocabulary (ability to understand individual words) for children and adults ages 2 years 6 months to 90 years and older. Standard scores are derived from number correct. Standard scores can range from a minimum of 40 and 160. Standard scores between 85 and 115 (1 standard deviation above and below the mean of 100) are interpreted as reflecting receptive vocabulary levels expected for age. Scores below 85 are interpreted as reflecting receptive vocabulary levels below what is expected for age.Scores above 115 are interpreted as reflecting receptive vocabulary levels above what is expected for age.

Time frame: Test completed at start of study

ArmMeasureValue (MEAN)Dispersion
Children With Developmental Language DisorderPeabody Picture Vocabulary Test, Fifth Edition98.07 score on a scaleStandard Deviation 11.28
Children With Typical Language DevelopmentPeabody Picture Vocabulary Test, Fifth Edition116.69 score on a scaleStandard Deviation 10.98
p-value: =0.54t-test, 2 sided

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026